In the earth-ocean-atmosphere system, the halogenated species take part in the cycles of several key processes involving both gas and heterogeneous interactions. The atmospheric cycles of reactive halogens are very complex specifically for those emitted from natural sources. As far as their roles in the tropospheric chemistry, the halogen compounds particularly those containing bromine (Br) and...

[1] We use the GEOS-Chem chemical transport model to interpret observations of tropospheric ozone from the Tropospheric Emission Spectrometer (TES) satellite instrument in summer 2005. Observations from TES reveal elevated ozone in the middle troposphere (500–400 hPa) across North Africa and the Middle East. Observed ozone abundances in the middle troposphere are at a maximum in summer and a mi...

Abstract. We examine whether the individual ozone (O3) measurements from the four Aura instruments can quantify the stratosphere-troposphere exchange (STE) flux of O3, an important term of the tropospheric O3 budget. The level 2 (L2) Aura swath data and the nearly coincident ozone sondes for the years 2005–2006 are compared with the 4-D, high-resolution (1×1×40-layer× 0.5 h) model simulation of...

The stability characteristics of normal mode perturbations on idealized basic states that have meridional potential vorticity (PV) gradients that are zero in the troposphere, very large at the tropopause, and order b in the stratosphere are checked. The results are compared to the corresponding models that have a lid at the tropopause. The dispersion relations and the vertical structures of the...

Extratropical tropospheric variability is investigated during Northern Hemisphere winter in the context of feedbacks between the meridional slope of the isentropic surfaces and the generation of eddy activity in the lower troposphere. The results reveal that at mid-high latitudes, periods of anomalously large tropospheric eddy heat fluxes (and thus wave generation) are preceded by anomalously s...

The hypothesis of convective quasi-equilibrium states that moist convection reacts almost instantly to drive the atmospheric temperature profile throughout the troposphere to one of a special subset of possible profiles. In a simple case this might consist of a moist adiabat with the saturated moist entropy of the adiabat equaling the moist entropy of the boundary layer. In more complex cases t...

Results from a global three-dimensional model for tropospheric O3-NOx-hydrocarbon chemistry are presented and evaluated with surface, ozonesonde, and aircraft measurements. Seasonal variations and regional distributions of ozone, NO, peroxyacetylnitrate (PAN), CO, ethane, acetone, and H2O2 are examined. The model reproduces observed NO and PAN concentrations to within a factor of 2 for a wide r...

Oxidized mercury (Hg(II)) is chemically produced in the atmosphere by oxidation of elemental mercury and is directly emitted by anthropogenic activities. We use the GEOS-Chem global chemical transport model with gaseous oxidation driven by Br atoms, to quantify how surface deposition of Hg(II) is influenced by Hg(II) production at different atmospheric heights. We tag Hg(II) 10 chemically produ...

This study examines the interannual variability of winter upper-troposphere water vapor over the Northern Hemisphere using the National Aeronautics and Space Administration Water Vapor Project, the International Satellite Cloud Climatology Project data, and the European Centre for Medium-Range Weather Forecasting reanalysis. The El Niño–Southern Oscillation related tropical sea surface temperat...